Don't be afraid of exposing yourself through conversation — seize every opportunity to chat with others in English. Before long, you'll feel at ease in informal settings.
Literal
Talking [nominalizer-こと] [by means of-で] self [object-を] expose [nominalizer-こと] [object-を] not-fearing, English [in-で] others [with-と] chat every opportunity [object-を] seize [soft imperative-なさい]. So-do [conditional-すれば] soon informal conversation [possessive-の] scene [in-で] at-ease can-become [formal conjecture-であろう].
A dense passage clearly translated from English-language learning advice. ~であろう is a formal conjecture ('it will probably be...') typical of written/academic style. 形式張らない ('informal, not stiff') is a negated form of 形式張る. The overall tone is stiff — few native speakers would structure advice this way naturally.